JPS6269435A - Removing method for foreign particle in cathode-ray tube - Google Patents

Abstract

PURPOSE:To intend to remove foreign particles in a cathode ray tube efficiently by applying vibrations of a vibrator and shocks by tapping and so on simultaneously to the bulb. CONSTITUTION:The bulb 2 provided with the shadow mask 1 is held on the bulb holder 3 so as the neck is downward, and the bulb holder 3 is directly connected to the vibrator 5 fixed on the base plate 4. When the vibrator is oscillated to transmit the vibration to the bulb 2 through the bulb holder 3, and simultaneously the tapping hammer 6 is operated to apply the shock to the surface of the bulb 2, foreign particles are freed from the inside surface of the bulb 1 to fall downward. Thereby defects of mask clog caused by adhesion of fine foreign particles on the mask can be reduced, and at the same time, the insulation defect caused by the movement of foreign particles to the electron gun part can be prevented to improve the quality significantly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for removing foreign matter from a cathode ray tube, and more particularly to a method for removing foreign matter from a shadow mask type compact color cathode ray tube of 10 inches or less and similar cathode ray tubes. .

[Background of the invention]

Ultra-small color cathode ray tubes use shadow masks with a mask pitch of 0, for example, 300 μm.

Even if foreign matter of about 50 μm remains inside the tube, it can cause surface defects. Therefore, in the step before sealing the electron gun to the cathode ray tube bulb, the entire neck of the bulb is held downward to remove foreign matter inside the bulb.

(For example, see Japanese Patent Application Laid-open No. 58-23146.) Conventionally, methods for removing such foreign substances include applying vibration to the valve using a 79ibrator, applying impact such as tapping to the valve, and applying an air blower inside the valve. I don't know how to blow air.

The method using a distributed vibrator has the effect of helping the movement of foreign matter, but it is difficult for the foreign matter to be released from the inner surface of the valve, making it difficult to remove all the foreign matter.

Methods such as tapping described above are effective in completely releasing foreign matter, but the movement of the foreign matter is small (C).

It takes a lot of time. In the method using air blow, fine foreign particles are suspended [1. It is difficult to remove it outside of YZ Lube.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for removing foreign matter from a cathode ray tube, which can liberate foreign matter from the inner surface of the bulb, move the foreign matter all the way down, and effectively remove it from the outside of the bulb.

[Summary of the invention]

According to the present invention, "Fe" is applied to the valve at the same time as shooting with a vibrator and hitting such as tapping. As a result,
Foreign matter within the valve is effectively removed to the outside of the valve.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In preparation for the shadow mask 1, two 1ζ bulbs are held in a bulb holder 3 with the neck fully downward, and the bulb holder 3 is fixed to the base plate 4. It is directly connected to the built-in Vibrake 5. Moreover, above the valve surface of valve 2, (
2) A tapping hammer 6 is provided which is vertically swung by a cam (not shown).

Therefore, when the vibrator 5 is oscillated and the vibration Dk is transmitted to the valve 2 via the valve holder 3, and at the same time the tapping hammer 6 is activated to strike the valve surface of the valve 2, the foreign object 7 is removed from the inner surface of the valve l. At the same time, it is moved downward.

Next, we will discuss the results of an experiment in which a shadow mask type 6-inch color cathode ray tube bulb was set in the foreign matter removal device. Approximately 50 pieces of white chalk powder with a diameter of about 50 μm was charged in advance into bulb 2, and the foreign matter removal rate was compared by measuring the amount of chalk powder removed below the neck by applying vibration. The vibrator 5 has an amplitude of 5tm,
5 QHz vibration and tapping hammer 6nl
A blow of approximately 3 G was applied to valve 2 by an 80 rpm (7) cam.

Even after 60 seconds, the knitting by vibration of Vibrake 5 only removed 70 parts of the foreign matter in the pulp by only πV, making it difficult to completely remove it. Under the condition of using only the tapping hammer 6, the foreign matter inside the valve was completely removed after 40 seconds. On the other hand, according to the method of adding the pie break 5 and the tapping hammer 6 of the present invention at the same time, all the foreign substances in the pulp were removed after 20 seconds, and it was found that the removal effect was greater than that of the conventional method. .

〔Effect of the invention〕

As is clear from the above description, according to the present invention, vibration by a vibrator and impact such as tapping are simultaneously applied to the valve, so that all foreign matter is liberated from the inner surface of the valve, and at the same time, the foreign matter is moved downward. Can be effectively removed outside the valve. This reduces mask clogging and defects caused by minute foreign matter adhering to the shadow mask, and also prevents foreign matter from moving to the electron gun section and causing insulation defects, thereby significantly improving quality.

[Brief explanation of drawings]

The figure is a conceptual diagram showing one embodiment of the present invention. 2...Valve, 3...Valve holder, 5.
...vibrator, 6...tapping hammer.

Claims (1)

[Claims] In the step before sealing an electron gun to a cathode ray tube bulb, the bulb is held with its neck facing downward, and foreign matter inside the bulb is removed by simultaneously applying vibrations by a vibrator and impact such as tapping. How to remove foreign matter from cathode ray tubes.